Crystal and molecular structures of 4-substituted 3,4-dihydropyrimidin-2(1H)-ones studied by X-ray and AM1 and B3LYP calculations

publication · 8 years ago
by Ignez Caracelli, Julio Zukerman-Schpector, Vega- Mauricio Teijido, Fábio Macedo Nunes, Paula M. Gatti, Hélio Alexandre Stefani (Universidade Federal de Sao Carlos)
(1) C13H13N3O5, Mr = 291.26, P-1, a = 7.4629(9), b = 7.9203(9), c = 12.126(2) Å, α = 86.804(5), β = 78.471(7), γ = 69.401(8)°, V = 657.3(2) Å3, Z = 2, R1 = 0.0454; (2) C11H12N2O4, Mr = 236.23, Pbca, a = 7.2713(9), b = 14.234(1), c = 20.848(3) Å, V = 2157.8(4) Å3, Z = 8, R1 = 0.0504; (3) C13H13N2O3Cl, Mr = 280.70, P2/n, a = 17.344(2), b = 9.237(1), c = 18.398(2) Å; β = 92.61(2)°, V = 2944.4(6) Å3, Z = 8, R1 = 0.0714. The conformational features of three 4-substituted-3-4-dihydropyrimidin-2(1H)-ones were investigated by computational and single crystal X-ray crystallographic studies. The geometries were optimized using semiempirical (AM1) and first principle calculations (B3LYP/6-31G**) methods, the rotational barriers for important functional groups were studied. In all structures the pyrimidinone rings are in a more or less distorted boat conformation. The phenyl and the furane rings are almost perpendicular to the best least-squares plane through the dihydropyrimidinone ring.
Visit publication